During the years 1890 to 1892 the Swedish botanist and explorer Per Karl Hjalmar Dusén (1855-1920) collected about 560 nicely preserved impression leaf fossils in a dark brownish to yellowish basaltic tuff in the surroundings ofMountCameroon , at the west coast of Cameroon. Dusén mentioned these plant remains in his account on the geology of northwestern Cameroon (Dusén, 1894) but the only palaeobotanical study of these fossils was undertaken by the German palaeobotanist Paul Menzel (1864-1927).
Both Dusén and Menzel referred the fossil plants to species growing today in the Mt.Cameroon area. However, the exact age of the fossils is unclear; Dusén vaguely suggested a “Tertiary or Quaternary" age.
According to Jean Maley (pers. comm., August 16, 1994) the age of the fossiliferous tuffs is Quaternary and most probably late Quaternary.